128705187 has 8 divisors (see below), whose sum is σ = 184807504. Its totient is φ = 79203168.

The previous prime is 128705177. The next prime is 128705189. The reversal of 128705187 is 781507821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128705187 - 2⁶ = 128705123 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 3300133 = 128705187 / (1 + 2 + 8 + 7 + 0 + 5 + 1 + 8 + 7).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128705189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1650028 + ... + 1650105.

It is an arithmetic number, because the mean of its divisors is an integer number (23100938).

Almost surely, 2^128705187 is an apocalyptic number.

128705187 is a deficient number, since it is larger than the sum of its proper divisors (56102317).

128705187 is a wasteful number, since it uses less digits than its factorization.

128705187 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3300149.

The product of its (nonzero) digits is 31360, while the sum is 39.

The square root of 128705187 is about 11344.8308493340. The cubic root of 128705187 is about 504.8922254733.

The spelling of 128705187 in words is "one hundred twenty-eight million, seven hundred five thousand, one hundred eighty-seven".